SpeedSpeak2Me

Don't forget to take in coax loss before calculating the ERP though. I thought the coax type was mentioned but not seeing it If using something like RG-8X then there will be substantial loss at 460-470 MHz, about 8.6 - 9.0db per 100'. So need to figure that loss in before the gain of the antenna. Knowing which coax is being used, plus total length would help with calculating the ERP. Just some information, but I have Browning BR-6155 (5/8 stacked, 5 dBd gain) mounted where the base of the antenna is about 15' AGL (antenna is 76" tall), and can key repeaters at 30 miles using just 0.4w, with enough audio to carry on a conversation. For the repeaters at 40+ miles I only need 2.5w. The antenna is pre-tuned for 450-470 MHz, and as being fed with 50' of LMR400. Mostly flat around here, and can have simplex communications with ground (car) units out to about 8-10 miles. Base to base about 10-15 miles. Previously the antenna base was at 40', and my simplex comms were 20-25 miles for base-to-base, and around 15 miles for mobile. Before finding a rig that will push 100w+, I'd make sure the coax I was using was as low-loss as I could afford, and then get a very efficient antenna. Something else to consider is the terrain. If it's flat, the something like a 1/2 wave antenna would be better, as its azimuth lobes are low down and cover greater distance. 5/8 wave would be the next best for some hilly terrain.

I'm thinking about getting one, to both test out and to have if I am off-roading, so I don't catch the whip on branches and damage it. From what I've seen, it is also an excellent performer.

I'm looking at my data now for the Laird. Down at 440 MHz you could still use this antenna, as it's at 1.66:1. I could have left it about 1/4" - 3/8" longer and tuned it for 455-460 MHz instead, and it would have been about 1.5:1 for 70cm and about 1.35:1 for GMRS repeater inputs. I really am impressed with it.

I picked up the Laird BB4503 for use with a mag mount and RG-8X. Out of the box it is tuned right about 452-453 MHz (using a Rig Expert Stick Pro). They give you exact trimming lengths to use, spaced at 5 MHz intervals (450, 455, 460, 465, 470 MHz). I'm within 1/8" from their 465 MHz measurement and have a nice flat curve throughout the entire GMRS band, IIRC about 1.2:1. I wouldn't have any issues picking up another one, and just might. The Midland MXTA26 is an exceptional antenna as well if you have the room for it. Another option is the Browning BR-450 UHF, which also requires trimming and is a tall antenna. Those that I've spoken to that own them have been very happy with their quality and performance.

I'm have the exact same issue. I have both the UT-72 and the UT-72G, and the 72G's UHF tuning appears to be in the 70cm band (centered on 440 MHz). With a Surecom SW-102 it's pretty much flat for 2m and MURS, about 1.1:1 for 70cm, almost 1.5:1 for GMRS simplex (462 MHz), and well over 2.1:1 on the repeater inputs (467 MHz). Using a NanoVNA (calibrated 400-500 MHz using 401 data points) it is showing the same. The "plain" UT-72 has better readings using both the meter and analyzer on the 462-467 MHz range than the UT-72G does, and it's quite disappointing, and somewhat frustrating. I know others that have the UT-72G and they're tuned for center of the GMRS band, right around 464 MHz, and are less than 1.25:1 across the band. Both came antennas came in identical bags, which do appear to be authentic Nagoya. The UT-72G bag has a second sticker/label covering the original. So UT-72 underneath, UT-72G on top. They are basically identical expect the UT-72G's mast/whip is about 1" shorter than the UT-72's, which is about right for tuning up a 70cm antenna for 64cm, and for bringing a 2m antenna up to MURS. Unfortunately neither are adjustable, unless you pull the rubberized protective cap off the whip and trim it back, then use something else to protect the end. When testing with the Surecom I used a double-male PL-259 connector so that the transceiver was directly connected to the meter, and took out any possibility of the jumper cable being an issue. Conversely I have a Diamond MR-77 that was tuned at > 1.3:1 for 2m and 70cm (center band for both) right out of the box. Since it was an extra antenna, and tunable, I trimmed off about 20mm, and it is now centered at 464.500 MHz, right in the middle of the GMRS range. I'm not worried about it on the VHF side, since it'll never be used for it. But 2m is still workable, with the NanoVNA showing it to be centered at 147.500 MHz (upper end of the band), at about 1.2:1 with a nice shallow dip covering a bandwidth of 10-12 MHz.